a-delete freezes on empty bucket without --rmb

[iljah]

Had an empty bucket ace_runs which I tried to delete but a-delete seemed to freeze:

$ a-delete ace_runs                
swift connection OK
Object name: ace_runs not found in allas.
^C
$ Traceback (most recent call last):
  File "/appl/bin/swift", line 6, in <module>
    from swiftclient.shell import main
  File "/appl/soft/bio/bioconda/miniconda3/lib/python3.7/site-packages/swiftclient/__init__.py", line 20, in <module>
    from .client import *  # noqa
  File "/appl/soft/bio/bioconda/miniconda3/lib/python3.7/site-packages/swiftclient/client.py", line 65, in <module>
    from keystoneclient import exceptions as ksexceptions
  File "<frozen importlib._bootstrap>", line 1032, in _handle_fromlist
  File "/appl/soft/bio/bioconda/miniconda3/lib/python3.7/site-packages/keystoneclient/__init__.py", line 72, in __getattr__
    return importlib.import_module('keystoneclient.%s' % name)
  File "/appl/opt/anaconda3/2019.3/envs/default/lib/python3.7/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
  File "<frozen importlib._bootstrap>", line 983, in _find_and_load
  File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 724, in exec_module
  File "<frozen importlib._bootstrap_external>", line 818, in get_code
  File "<frozen importlib._bootstrap_external>", line 917, in get_data
KeyboardInterrupt
^C

$ a-delete --rmb ace_runs worked though.